3 MEMBERS OF THE HUMAN CYSTATIN GENE SUPERFAMILY, AHSG, HRG, AND KNG,MAP WITHIN ONE MEGABASE OF GENOMIC DNA AT 3Q27

While constructing a contig in the human chromosome region 3q27, we id entified two YAC clones that were positive for the polymorphic marker D3S1602. One of these clones was also positive for a sequence-tagged s ite derived from the kininogen (KNG) gene. Because of the known evolut ionary and structural relationship of KNG to other members of the cyst atin gene superfamily, we tested the physical linkage of the genes enc oding alpha-2HS-glycoprotein (AHSG), KNG, and histidine-rich glycoprot ein (HRG), all of which were previously mapped to the long arm of chro mosome 3. Our results show the colocalization of the three genes in tw o independent, partially overlapping YAC clones. The genomic inserts o f the two clones were 1 Mb and 1.3 Mb in size, indicating that the thr ee genes map within 1 Mb of DNA. The largest YAC was also positive for the polymorphic marker D3S1262, substantiating previously reported da ta of genetic linkage between this marker and HRG. Fluorescence in sit u hybridization localized the two YAC clones to chromosome band 3q27.